(a) Field
The invention relates to a display device, and more particularly, to a display device generating a sound or vibration in addition to displaying an image.
(b) Description of the Related Art
Display devices have been developed from a cathode ray tube (“CRT”) to various flat panel display devices such as a liquid crystal display (“LCD”), a plasma display panel (“PDP”), an organic light emitting display (“OLED”), an electrowetting display (“EWD”), an electrophoretic display (“EPD”), an embedded micro cavity display (“EMD”) and a nano crystal display (“NCD”).
Since the LCD which has been in the limelight among the flat panel displays has advantages such as a small size, a light weight and low power consumption, the LCD has gradually received attention as a replacement means capable of overcoming disadvantages of the CRT. The LCD has been installed and used on almost all information processing devices requiring a display device. The LCD is a device in which a liquid crystal panel includes a liquid crystal material is between an upper substrate where a common electrode, a color filter and the like are disposed, and a lower substrate where a thin film transistor, a pixel electrode and the like are disposed. Different electrical potentials are applied to the pixel electrode and the common electrode to form an electric field to change alignment of liquid crystal molecules in the liquid crystal material, thereby controlling transmittance of light to express an image by the LCD.
In the LCD, since the liquid crystal panel is a non-emissive element which does not self-emit light, the LCD further includes a backlight unit for providing the light to the liquid crystal panel from the lower portion of the liquid crystal panel.
In contrast, the OLED among the flat panel displays includes a light emitting diode (“LED”) self-emitting light and thus does not use the backlight unit.